Surgical retractors for holding tissues, at the edge of a surgical incision or wound, away from the field of an operation have been in use for several decades. Early designs such as shown, for example, in Smith U.S. Pat. Nos. 2,586,488 and 2,594,086 provide an annular or ring-like support which is laterally and vertically adjustable along a mounting assembly adapted to be secured to an operating table. Disposed at intervals around the annular support are a plurality of slide arms having bendable retracting elements at their inwardly extending ends which contact the skin, viscera or organs in the field of operation and retain them out of the surgeon's way while the operation is being conducted. Relatively awkward and cumbersome securing means are provided to attach the slide arms in place on the annular support. Similar devices have been utilized for performing operations on the brain such as shown, for example, in Lake U.S. Pat. No. 3,766,910. Such retractors extend inwardly from the ring's top surface, and are clamped or otherwise secured along the top surface of the ring.
The so-called Greenberg retractor and handrest assembly is currently one of the most popular retraction devices used by neurosurgeons. The Greenberg assembly consists of a single or multiple support bars which are clamped together end-to-end beginning with one support bar attached to the skull clamp used to hold the patient's cranium securely in place during an operation. One or more retractor support arms having flexible blades at their inwardly extending ends are movably mounted to the support bars and are slidable therealong for positioning the support arms and flexible blades at desired locations to provide suitable retraction at the incision. Care must be taken in adjusting the position of the clamps because they may be loosened to the point where they will fall off the support bars. Additional retractor support bars and support arms may be added to provide further retraction capability as the operation progresses.
The problem of difficult and inconvenient adjustment of the position of the retractor arms is common to the Greenberg system and many of the other prior art devices. In some designs, further assembly of parts during the operation is required to obtain the desired number and positioning of retractor arms. Even those who have had experience in using such systems may find it difficult to quickly perform the necessary assembly as the operation progresses. In addition, the large number and orientation of elements which make up a system such as the Greenberg assembly tends to obstruct the surgeon's view and get in the way as the hands are shifted from one position to another during the operation.
It has therefore been an object of this invention to provide a surgical retractor which is simple in construction and needs no further assembly once the operation is in progress.
It is another object of this invention to provide a surgical retractor in which flexible retractor arms are slidably and removably captured within a channel formed in a ring support, for rapid and easy adjustment of the position of such retractor arms during an operation.
It is a further object of this invention to provide a surgical retractor having a ring support defining the field of the operation which support serves the dual purpose of positioning arms for retracting tissue from the incision and also acting as a stabilizing handrest for the surgeon.